Solar Power Satellites

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As the needs of ourplanet's ever-increasing population grow to unprecedented highs, the search for anew and more efficient way of powering our industries, businesses, and homes isbecoming a very pressing priority. The techniques we use today to generate powerare simply detrimental in the long run; burning fossil fuels or splitting atomsgenerate a lot of power, but also damage the planet with pollution, andalternatives like wind and hydro power can be limited both geographically andseasonally.

As replacement technologies are pondered, one stands out.Instead of manipulating existing elements of Earth, this inventive proposal plansto collect solar energy from space and transmit it back to the surface usingsolar power satellites (SPS). Directly harnessing the energy of the sun allowsmankind to preserve the well-being and resources of Earth while producing enoughenergy to satisfy the needs of the growing human race hundreds of times over.

First proposed in 1968 by Dr. Peter Glaser of NASA, these satelliteswould use large solar panels in space to collect the sun's light energy. Oncecollected, the energy would go through two conversion phases. First, it would besent through onboard photovoltaic cells to be converted into electrical energy.Afterwards, the electrical energy would be channeled into large microwavegenerators where, using the principles behind the wireless power transmission ofenergy (WPT), it would be converted into controllable microwaves and beamed downto earth. On the surface, large antennas would pick up the beam and reconvert themicrowaves into electrical power, which could then be plugged into the localpower grid to use.

At first, solar power satellites were nothing morethan hopeful dreams of scientists, but recent advances have propelled them intothe reaches of reality. Satellite technology has developed to the point wheretelecommunication companies use satellites for everything from cell phones totelevision transmission. Would their use as "orbiting power lines" besuch a stretch? The WPT system has also gone through comparable progress,especially since the development of adequate antenna technology. Though energyconversion efficiencies from electrical energy to microwaves and then back toelectricity are currently around 54% , WPT transmissions to a helicopter, a smallaircraft, and a satellite from a launched rocket have all been successful,demonstrating that WPT can indeed be used to power or receive power from flyingbodies. (Brown, Singh, 187) Computing technology is also advanced enough tocontrol satellites and allow them to change position without interrupting arunning microwave beam.

Solar power satellites are attractive venturesfor many reasons. Foremost, by using the sun, humans could acquire all thenecessary energy without causing pollution, threatening species, or generallydamaging the Earth. Second, the sun's power is limitless and perpetual.

By carefully placing the satellites on certain points over the equator,they would be exposed to sunlight 24 hours a day, ensuring a constant receptionand flow of energy. The power output would then only depend on how manysatellites were in space; a whole network could potentially generate exponentialamounts of usable energy! A third reason solar power is attractive is because theconstant energy flow and bulky, expensive storage facilities would no longer beneeded, minimizing costs and increasing availability. Fourth, since there are noweather or atmospheric disturbances in space, the solar panels would be exposedto more sunlight and have a greater efficiency than panels placed anywhere on theEarth's surface (Singh, 188).

Microwave beams have been tested extensivelyand are deemed safe by organizations such as the U.S. National Research Councilof the Academy of Sciences (Preble). Unlike x-rays or ultra-violet radiation,microwaves are non ionizing and are one million times too weak to cause harm(SUNSAT Energy).

The only perceivable effect is heating, but since thepower density of the beam near the receivers on Earth is about 20 milliwatts persquare centimeter, one-fourth of natural sunlight, the heat generated is soslight that a person walking through would feel nothing. Manufacturing costs arenot a problem either, since materials would be negligible (when compared with therelatively giant profits that a solar power satellite would generate).

Sowhy hasn't a solar power satellite been built? Well, there is no scientificreason. Photovoltaic cells, satellite technology and microwave beams have allbeen explored and researched sufficiently to operate solar power satellites. Withall the components available, it just seems a matter of time. Do not forget thatit was only a short time ago that there were no satellites at all.

Without a doubt, solar power satellites hold significant promise to becritical components for the upcoming centuries. Their benefits are extraordinary- the preservation of our planet, a limitless power source, a constant flow ofenergy, no serious safety threats, and a practical business side. As SPStechnology could supply our planet with trillions of watts at one time, it couldeasily provide for the ever-growing population of Earth.

Mark's extensivebibliography can be found at:http://TeenInk.com/Past/2001/November/Environment/SolarPower